I am having a problem retrieving my external ip address. I have a router provided by T-Com in Croatia which I do not have admin access to. Behind it I have a router running Tomato with an OpenVPN client active. What I want to do is have the Tomato router update OpenDNS with my T-Com routers external ip - not my OpenVPN address.

In my Tomato routers DDNS section, If I pick my WAN address it gives me the address of my Tomato router on my T-Com router. If I pick external ip address checker, it gives me my OpenVPN address. Neither help me out since all other traffic goes through my T-Com router.

I think I need to add a different route on my Tomato router to access the external ip of my T-Com router but can't figure out what I need to do. Can someone give me a tip on how to do this?